The Department of Justice has launched a civil rights probe of the prisons.

A 54-year-old inmate died this week at Mississippi’s most notorious penitentiary, the 16th prisoner since late December to perish in the state’s correctional facilities, where living conditions have been called inhumane and which have been beset by cellblock murders, suicides, riots and escapes.

James Allen Brown, 54, a convicted murderer serving a life sentence at the Mississippi State Penitentiary at Parchman, died on Monday, according to the Sunflower County Medical Examiner’s Office.

Heather Burton, the county coroner, said there’s no evidence of foul play, telling ABC affiliate station WLOX-TV in Biloxi that Brown, who began his term in 1993, “was in the inpatient department and had been receiving treatment for a terminal illness.”

The cause of Brown’s death is pending autopsy results.

The death comes less than a week after the Department of Justice announced its Civil Rights Division’s Special Litigation Section is launching an investigation into conditions at four Mississippi prisons, including Parchman.

DOJ officials said the investigation will focus on whether the Mississippi Department of Corrections adequately protects prisoners from physical harm by other prisoners “as well as whether there is adequate suicide prevention, including adequate mental health care and appropriate use of isolation, at Parchman.”

The federal investigation is being conducted under the Civil Rights of Institutionalized Persons Acts, which gives the DOJ authority to investigate violations of prisoners’ constitutional rights that could result from a “pattern or practice of resistance to the full enjoyment of such rights,” the DOJ said in a statement.

Besides Parchman, the DOJ plans to investigate conditions at the South Mississippi Correctional Institution in Leakesville, the Central Mississippi Correctional Facility in Pearl and the Wilkinson County Correctional Facility in Woodville.

The DOJ probe comes roughly a month after 11 prisoner advocacy groups, including the American Civil Liberty Union of Mississippi, the Southern Poverty Law Center and the Mississippi State Conference of the NAACP, sent a 23-page letter to the DOJ requesting a federal investigation.

Since Dec. 29, 10 of the 16 deaths in the correctional system have occurred at Parchman, including five inmates who were fatally stabbed or beaten to death by other inmates, and three who died by suicide, officials said.

The latest death at Parchman came on the same day Mississippi Gov. Tate Reeves extended an emergency order allowing the state to immediately spend money on resolving problems in the prison system.

Reeves has made fixing the prison system a top priority of his administration. One of Reeves’ first acts after taking over as governor on Jan. 14 was to visit the penitentiaries.

He announced a series of “common sense” changes he’s begun implementing, including a crackdown on contraband cellphones, which, he said, have been used to coordinate violence throughout the prison system. He’s also seeking a process to weed out corrupt or gang-affiliated guards.

In his first State of the State address, Reeves said he’s instructed the Mississippi Department of Corrections to close Unit 29 at Parchman, where an inmate was killed and several others injured in a Jan. 2 riot that prompted a temporary statewide lockdown.

The problems at Mississippi prisons have attracted the attention of hip-hop artist Yo Gotti and music mogul Jay-Z, who supported a federal lawsuit filed last month on behalf of 29 Mississippi prisoners who accused state correctional officials of doing little to stop violent outbreaks.

“Plaintiffs’ lives are in peril,” the lawsuit said. “These deaths are a direct result of Mississippi’s utter disregard for the people it has incarcerated and their constitutional rights.”